Garage Conversion ADU in Tamiami: Scope, Timeline & What It Costs
A garage conversion ADU in Tamiami turns your existing attached or detached garage into a permitted dwelling unit with its own kitchen, bath, sleeping area, and separate entrance. Most projects run 3 to 5 months from permit approval to final inspection, with costs typically landing between $30,000 and $80,000 depending on what your existing structure needs. Call (844) 665-0162 and we’ll walk your garage with you, same week, no charge.
How We Convert a Garage to an ADU in Tamiami
We’ve done enough of these in west Miami-Dade to know where the surprises hide. Here’s the actual sequence, with the decisions you’ll need to make at each point.
Stage 1: Feasibility & zoning check (1-2 weeks)
We pull your property’s Miami-Dade zoning classification and verify setback, lot coverage, and parking replacement requirements. In Tamiami, many 1970s-1990s CBS homes were built right to their side setbacks, so we confirm the garage conversion won’t push you over coverage limits. You’ll decide at this stage whether you want a full kitchen or a kitchenette, and whether the unit needs to be fully metered separately or sub-metered. That choice drives our electrical and plumbing scope.
Stage 2: Structural assessment & HVHZ compliance plan (2-3 weeks)
Our engineer evaluates whether your garage slab can support the added load of a finished floor system, insulation, and fixtures. Many Tamiami garage slabs were poured as thin, unreinforced floating pads over that shallow water table. If we find cracks, inadequate thickness, or no vapor barrier, we’ll quote slab remediation or a new pour. You’ll also decide on impact-rated windows and doors here. Miami-Dade’s High-Velocity Hurricane Zone requires them for any new conditioned space, and most existing garage openings have none.
Stage 3: Permit submission & plan revision (4-8 weeks)
We submit to Miami-Dade Building Department with structural calcs, MEP plans, and energy compliance documentation. County review for ADU conversions typically takes 4-6 weeks, longer if the property’s older records are incomplete. We handle revision requests, but you’ll need to sign off on any changes that affect unit layout or ceiling height. Miami-Dade enforces minimum 7-foot ceiling height for habitable space; low garage ceilings often require floor lowering or roof raising.
Stage 4: Construction (8-14 weeks)
Demo of existing garage interior, then rough framing for any new interior partitions. We run new electrical service (or sub-panel), plumbing for kitchen and bath, and HVAC mini-split or duct extension. Insulation, drywall, flooring, and finishes follow. In Tamiami, we spec moisture-resistant materials throughout: cement board behind wet walls, vinyl or tile flooring instead of engineered wood, and closed-cell spray foam where budget allows. You’ll make your final material selections during week 2 of construction; we order then to avoid lead-time delays.
Stage 5: Inspections & certificate of occupancy (2-4 weeks)
Miami-Dade requires rough inspections for structural, electrical, plumbing, and mechanical, followed by insulation inspection, then final building, fire, and zoning. We schedule sequentially and correct any punch items before the next trade inspection. You’ll receive the certificate of occupancy once all are cleared. Total timeline from our first site visit to move-in day: typically 5 to 7 months.
The Spec Choices You’ll Make for Your Garage Conversion ADU
Every decision below affects cost, durability, and who your unit works best for. We lay out the trade-offs honestly.
- Foundation repair vs. new slab: If your existing garage slab is cracked, thin, or lacks a vapor barrier, we can patch and seal for $3,000-$6,000 or pour new for $8,000-$15,000. The patch route saves money but may limit flooring choices and won’t fix chronic moisture wicking. New slab is the right call if you’re finishing to rental quality or if the existing pad is below grade.
- Impact-rated openings: Required by code, but you choose the tier. Standard vinyl-impact windows run less; aluminum-impact or architectural-grade PGT or CGI frames cost more but hold finish longer against Tamiami’s salt air. For doors, a basic impact-rated steel entry satisfies code; a fiberglass Therma-Tru or Masonite with multi-point hardware adds security and feel.
- Kitchen configuration: Kitchenette (mini-fridge, two-burner cooktop, single-bowl sink) keeps the footprint tight and plumbing simple. Full kitchen with 24-inch range, dishwasher, and full-size refrigerator needs more gas or electrical service and more cabinet run. We source cabinets from KraftMaid or Wellborn lines depending on your finish preference and budget tier.
- HVAC approach: Ductless mini-split (Mitsubishi, Daikin, or equivalent) is simplest for a converted garage, with one outdoor compressor and one or two wall cassettes. Extending your main house ductwork rarely works; garage conversions are too thermally distinct and code requires separate control. Mini-split also gives your tenant or guest independent temperature control.
- Floor finish: Luxury vinyl plank (LVP) resists moisture and installs fast. Porcelain tile costs more but survives flooding events better, relevant in Tamiami’s flat terrain where water can back up through slab edges during heavy rains. Engineered hardwood looks warm but we don’t recommend it at grade here.
What Garage Conversion ADU Costs in Tamiami, FL
Garage conversion ADU projects in the Tamiami market typically range from $30,000 to $80,000. Where you land depends on five factors:
| Cost Driver | Low-End Scenario | High-End Scenario |
|---|---|---|
| Existing structure condition | Solid slab, sound roof, minimal repair | Slab replacement, roof raising, structural reinforcement |
| Unit size & complexity | Single-car garage, kitchenette, full bath | Double-car or oversized garage, full kitchen, laundry, separate meter |
| Utility relocation & service | Sub-panel, shared water heater | New electrical service, gas line extension, separate water heater |
| Material grade | Standard cabinets, LVP, basic fixtures | Semi-custom cabinets, tile flooring, premium fixtures, upgraded insulation |
| Permit & compliance scope | Standard ADU conversion, existing home already HVHZ-compliant | Triggering whole-home HVHZ upgrade, flood elevation issues, extensive plan revision |
Our written estimates include demolition, rough and finish carpentry, electrical and plumbing rough-in and finish, HVAC, insulation, drywall, flooring, paint, fixtures, and permit fees. They do not include separate utility connection fees charged by FPL or Miami-Dade Water and Sewer, landscape restoration, or your choice of furnishings and window treatments. Call (844) 665-0162 for an exact quote on your garage. Estimates are free.
What Tamiami Homes Specifically Do to This Job
Tamiami’s position at the edge of the developed grid, hard against the Everglades along US-41, creates conditions we don’t see even ten miles east. The shallow water table here, sometimes within inches of grade, means any garage slab work risks immediate groundwater intrusion. We’ve had dewatering pumps running continuously on jobs where we expected a simple footing dig. That limestone layer 12-18 inches down stalls excavation and adds cost that out-of-market contractors consistently miss in their bids.
The housing stock we’re working with is almost exclusively 1970s-1990s CBS construction from the westward suburban expansion. These garages were built as storage and parking space, not future living space. Ceiling heights run 7 to 8 feet. Slabs lack reinforcement. Electrical service is often a single 15-amp circuit. Bringing one of these into Miami-Dade’s current HVHZ compliance means impact-rated openings, proper anchorage, and often upgraded roof-to-wall connections. We handle that coordination as part of a full Home Additions & ADU in Tamiami project scope, so you’re not hiring a second contractor for structural remediation.
Stormwater is the other Tamiami-specific factor. The flat terrain means no natural drainage. After June through October downpours, water sits until it evaporates or pumps out. We design every garage conversion ADU here with slab edge waterproofing, proper grading away from the structure, and interior floor finishes that survive moisture events. It’s not optional. It’s what keeps your unit habitable.
Our Tamiami crews also coordinate with any applicable HOA requirements in the area’s single-family developments. Some restrict exterior appearance, parking space counts, or rental terms. We review covenants early so your project doesn’t stall on a rules violation after construction starts.
Homeowners completing a garage conversion ADU often pair the interior work with Cabinets & Countertops in Tamiami for the kitchen build-out, or with Backsplash, Tile & Flooring in Tamiami to unify the new unit’s finishes with a refreshed main house. Our Home Additions & ADU team manages both scopes under one contract.
Serving Tamiami, FL - Our Local Coverage Area
We’re based in the Tamiami area and know this community well. Use the map below to see our service coverage - if you’re nearby, we can almost certainly help.
Frequently Asked - Garage Conversion ADU in Tamiami
From permit submission to certificate of occupancy, expect 3 to 5 months of active construction plus 1 to 2 months for county plan review. Total elapsed time is typically 5 to 7 months. Call (844) 665-0162 to schedule a site review and we’ll give you a tighter timeline based on your garage’s condition.
Yes. Miami-Dade County requires building, electrical, plumbing, mechanical, and zoning permits for any garage conversion ADU. The property must also maintain required parking spaces after conversion, which often means adding a driveway pad or carport. We handle permit drawings, submission, and inspection scheduling as part of our standard scope.
Sometimes, but rarely completely. Most Tamiami garages have only a single electrical circuit and no plumbing. A legal ADU requires a kitchen sink, bathroom group, and dedicated electrical panel or sub-panel with AFCI/GFCI protection. We minimize utility runs by positioning wet walls near existing house stacks when possible, but some extension is almost always necessary.
The lowest-cost path is a single-car garage with sound existing slab, kitchenette instead of full kitchen, sub-panel fed from main house service, shared water heater, vinyl-impact windows, LVP flooring, and no structural changes. That combination can land near the $30,000 range. Every upgrade, from slab replacement to separate metering, moves the number up. Call (844) 665-0162 and we’ll price your specific garage.
We warranty our workmanship for one year from certificate of occupancy. Manufacturer warranties apply to windows, doors, cabinets, fixtures, and HVAC equipment per their terms. We pass all manufacturer documentation to you at project closeout and register warranties where required.
Start With a Free On-Site Estimate in Tamiami
We’ll walk your garage, check slab condition, ceiling height, and existing utilities, then deliver a written estimate with line-item pricing. No pressure, no deposit required to get the numbers. Call (844) 665-0162 or request a visit through our site. Raymond Estevez and our Tamiami crew will see you within the week.
Written by Raymond Estevez, Owner at Groundwork Construction Co., serving Tamiami and South Florida.